Seat support



H. L. HARMS 2,663,355 7 Dec. 22, 1953 SEAT SUPPORT Filed Sept. 20, 1947me m m L n m N Patented Dec. 22, 1953 agcasss are? ar happen harms u hSt- P lt sp in er Streets: Ser a Ne .1 1 2? Z laims- (01. 155-51) Myinvention relates "to an improvement in seat support and dealsparticularly with'a type. of support useful on tractors and othervehicles.

Tractor Seats'are usually" supported by means of a spring arm or similarstructure which allows a certain amountbfspring action as the tractorpasses over'the rough ground. Mos't'sat supports in common use producea' severe spring reaction whentheseat is' depressed. In some instancesrebound checking devices are provided to 'prevent thereturn'movement orthe seat to normal position faster than is desired.

It is the object of the present invention to provide a seat supportcomprising a parallel link mechanism with a tension spring mounteddiagbna'lly "across opposite c'orners' thereof. Thus as the mechanismis'actuated t-he seat is maintained at a constant angle and does notdisturb the balance of. the tractor operator.

A feature or thepresen'tinvention lies in the provisionofaparallellihkage having a diagonal spring as previously described. Asthe seat moves downwardly the spring elongates' tending to re-' turn'theseat to normal elevated positi'on, At the same time, however, the axis01; -the spring moves closer to the adjacent pivot center'lin'ediagonally across the linkage, thus tending to retard any severe springreaction.

A feature of the present invention lies in the provisionof a linkage vvhi'ch'tends to maintain the operator in'a'leve1 position.i'Whileoppos'ite sides of the seat support areconnectedtogether,

the connections and'pivotsaiesufficiently free to allow one side of the;support to be depressed a greater distance 'th'alr'i'the other sidethereof. As a result when one side of the tractor drops theoperator'tends to 'shift his weighttoward the opposite side of the'tractor,'thu's depressing the spring support on the ODDQfiiFQ side ofthe tractor nd endin to hold the operat r in a vel nos tion. v

These and otherobjects and 'novel features of my invention will be moreclearly and fully set forth i'nthe following specification and claims.

In'the drawings forming 'a' part'of mv'specification: a

Figure 1 is a perspective view of a tractor showing my seat support inplace thereupon.

Figure 2 is a side elevational view of my seat support.

Figure 3 is a top plan view of one side of my seat support showing theconstruction thereof.

Figure 4 is a rear elevational view of my seat support.

My seat support A may be used for any desired purpose but isparticularly designed for use on a tractor or similar vehicle designedto travel over rough ground. Accordingly in Eigurl of. the drawings'theseat SupportA is shown at-. tached to a tractor B. for supporting thetractor operator. The tractor Bis provided with a pairgoi parallel framemembers [0. and ll to which the. seat's'upport is attached, as bestillustrated in Figures 2 and 4 of the drawingsf The seat itself;identified by the numeral l.2,is attached to the upper end of the seatsupport A in any convenient manner. The seat support A includes agenerally U-shaped bracket ll3which is supported in ine verted position.The member l3 includes a'pair of substantially parallel side arms l4'and I5 which are connected by angularly inclined bracket portions 16 to"a transversely extending top con.- necting member It! forming the baseof; the U..

A pair of parallel supporting arms l9, and 20 are boltedto the tractorframe members. HI and H, The intermediate portion oIfeach oi thesevertical arms is pivotallyconnected to a link connecting the supportingarm .to the uvshapled bracket 13. A link"22 'ispivptally connectedat2?.v to the upper extremity" of 'the"ai'm'illl. The

pivotal connection 23 is "positioned ata point. spaced from theforjwardend of-. the link 22. A link, similar; toth'e link 22, is pivotally con;nected to the supporting'yarm" l8 at a pivot'pIoi-nt 25. The pivotpoint, 25is spaced'from the fori-Y ward end-of the link 24. Pivots'fZGand 21 conmeet the -rear ends of the links 22 and 24, spectively, to theopposite sides '15 and I4 oi the u-shaped bracket 13,

The lower end of the bracket, side [4 is pivotally connected at 29toj'alink 3.0. The pivot 29 is spaced forwardly from the rear. end onthe link The forward end ot'the link'3ll'is pivotally connected at 3|tothe supporting arm [9. The. spacing 9i. the pivots 25, 21, 29 and 3'! issuch that'the links 24 and 3i}v are arrangedin parallel relation;Furthermore, the spacing'between the DiYQts'ZE and 2.1 is equal toth'espaci b tw cnthe. pivots 2 2 and 31 so that 5 1. lill fi Z l g 3Q l illli l lli stant v Paralle rc ai qnshin- F Th low r. end s t- 22 parse s e15 s a r otally connected at 32t'o a link"33.""Th links? is pivotallyconnected at 34 to the vertical arm 20. The links 22 and 33 are inparallel relation and the spacing between the respective pivots is suchas to hold these links constantly parallel.

The forward end 35 of the link 22 is bent transversely' and angularly sothat the flat side thereof is substantially normal to a diagonal lineconnecting the front end of the link 22 to the rear end of the link 33.The rear end 36 of the link 33 is bent parallel to the link end 35 asbest illustrated in Figure 2 of the drawings. A spring 31 has one end 33connected to the end 36 of the link 33. A spring anchor 40 is providedat the other end of the spring 31' and an adjustment bolt 4! extendsthrough the link end 35 and is adjustably connected to the springanchor. By rotating the anchor bolt 4| the tension of the spring 31 maybe adjusted.

The forward end 42 of the link 24 is bent outwardly into parallelrelation with the outturned end 43 of the link 38. A spring 44 isanchored to the arm end 43 and is provided with a spring anchor 5 at itsother end. An anchor bolt 46 extends through the link end .2 and isadjustably secured to the anchor 45. As a result the tension of thespring 44 may be adjusted by rotating the anchor bolt 46.

A stop arm 41 is adjustably secured on arm 20 by a bolt 49 or othersuitable means. This arm 41 may be rotated about the bolt 49 so as tohold the arm 4'! in adjusted position. A similar stop arm 50 isconnected to the supporting arm IS. The lower ends of the stop arms 4!and 50 engage against the links 33 and 33, respectively, to limitpivotal movement of these links in one direction.

A plate 5| is welded or otherwise transversely afiixed to the centralportion I! of the U-shaped bracket l3. This plate 5| is provided withspaced apertures 52 therein to which the seat l2 may be bolted. The seatI2 is provided with a plate 53 attached thereto and having lugs 54projecting downwardly therefrom for engagement with opposite sides ofthe plate 5|. The lugs 54 hold the seat from rotation about its verticalpivot, while the bolt or bolts 55 extend through the plate 53 and theplate 5| to hold the seat in adjusted position.

In the preferred form of construction of my seat support the variouslinks are provided with bushings or bearings therein to fit about thevarious pivot bolts. The pivot bolts are sufficiently loose in theirbearings to permit a certain amount of angularity between opposite sidesof the seat support. Similarly the supporting members are of sumcientlyflexible material to permit a certain amount of distortion withoutpermanent bending. As a result one side of the seat support may bedepressed a substantial distance below the other when necessary so as tocompensate for lateral angularity of the tractor or other supportingdevice.

It will be noted that as weight upon the seat is increased or as thesupporting device passes over a bump, the seat is depressed. The sidesof the U-shaped bracket l3 maintain parallel relation with thesupporting arms l9 and 20 and the links on each side of the seat supportremain parallel. However, the distance between the forward end of theupper links 22 and 24 and the rear ends of the lower links 33 and 30increase as the seat moves downwardly. This action stretches the springs31 and 44. However,

it will also be noted that as the springs elongate the axes of thesprings move closer to the adjacent pivots supporting the links. Inother Words as the seat moves downwardly the axis of the spring 31 movestoward the center line between the pivots 23 and 32 and the axis of thespring 44 moves toward a center line between the pivots 25 and 29. As aresult the leverage of the springs decreases as the length thereofincreases, tending to curb excessive spring reaction. As a result thetractor operator is returned gently to normal position after the unusualstrain upon the springs is relieved.

In accordance with the patent statutes, I have described the principlesof construction and operation of my seat support, and while I haveendeavored to set forth the best embodiment thereof, I desire to have itunderstood that obvious changes may be made within the scope of thefollowing claims without departing from the spirit of my invention.

I claim:

1. A seat support including a pair of upright supporting members, aninverted L -shaped bracket having sides in parallel relation to saidupright members, a pair of links connecting each side of said bracket toa corresponding upright member, one end of each link being outturned,the outturned end of one link of each pair being at the end thereofattached to said upright support while the outturned end of the otherlink of each pair is at the end thereof secured to said bracket, and aspring connecting the outturned ends of the links of each pair.

2. A seat support comprising a substantially vertical fixed elongatedmember, upper and lower elongated members one above the other, firstpivot means pivotally connecting the upper member to said fixed member,second pivot means pivotally connecting the lower member to said fixedmember, another substantially vertical elongated member spaced from saidfixed member, third pivot meanspivotally connecting the upper member tosaid other substantially vertical member, fourth pivot means pivotallyconnecting said lower member to said other vertical member, the portionsof said four elongated members lying between said pivots defining aparallelogram, and resilient means extending diagonally across theparallelogram and anchored to said upperand lower elongated members atpoints spaced from said first and fourth pivot means. I

HERMAN L. HARMS.

References Cited in the file of this patent UNITED STATES PATENTS

